BitLocker – Encryption on hard drive volume scope. – The main concern is performances and the fact that the whole drive is being encrypted.

Application level encryption – Not supported in SharePoint.

Third party products like Storage Point.

Please note that HIPAA requirements states that DBA won’t have access to the encrypted blub ( file/data ), one option is to use a third party tool like Storage point which move the data from SQL to a remote storage location and encrypt the blub.